Cement gun



April 15, 1952 A. F. LUKES 2,592,815

CEMENT GUN Filed March 2o, 194e v 2 SHEETS- SHEET 1 @LQ-f- 5 fw* Z- /6 ze Z6 Z0 i/oz A. F. LUKES April l5, 1952 CEMENT GUN 2 SHEETS-SHEET 2 Filed March 20. 1946 Fwd @i www atenteci pr. l5, 1,952

CEMENT GUN Adolph F. Lukes, Waterloo, Iowa Application March 20, 1946, Serial No. 655,862

This invention relates to cement guns, and particularly a device for uniformly feeding a mixture of cement and sand to a cement gun at the point of application. The device is also applicable for use in sand-blasting, and for blowing sand in foundry molds.

In previous devices in this field, there has been.

difficulty in obtaining steady and uniform flow of cement and sand mixture. mainly due to the fact that the material is dry and is difficult to motivate by air pressure, that is, it will not flow. However, if the quantities of dry materials are small, there is more likelihood of its owing or passing along gradually and uniformly upon the application of air pressure. I

The present invention overcomes the difliculty above mentioned to a great degree. The device ls designed so that a small quantity of the dry material is brought into the air stream at a time and the whole charge is not thrown into the air stream simultaneously, but is brought into it gradually, so that that small quantity Vof the material is driven along, a little at a time. Before each small charge of material is completely emptied into the air stream, the Ysucceeding charge begins to empty into the air stream. The procedure continues in vsuch a manner that a whole charge is never placed in the air stream at one time, nor is there ever a time when there is no material being placed in the air stream.

More specifically, the mechanism includesk a chain-like device made up of articulated links forming receptacles for cement and sand and` having solid perimeter' walls of appreciable depth. The links or receptaclespass'through a hopper of 'material for filling and then travel between resilient plates having registering openings forming a discharging chamber, and be' tween which the chain travels for discharging the material. The shape of these openings is an essential feature of the invention. They are roughly triangular in shape and have a small end disposed in a direction opposite to the direction of travel of the chain. The links carrying lthe materialy thereforek pass into the discharging chamber in such a manner that only a small portion ofthe material is exposed to air pressure at first, and then a progressively greater amount. The dimension of the discharging chamber in the direction of travel of the chain is greater than the linear dimension of each link. Therefore, due to the length and peculiar shape of the discharging chamber, before each link has passed to the point where its whole surface is This difficulty is 4 Claims. (Cl. 302-49) exposed in the chamber, the next succeeding link has entered the chamber at the small end thereof. By this time the first link is discharging material at a decreasing rate and the succeeding link begins to discharge material at an increasing rate, resulting in a flow of material.

With these and` other objects in view, my'in--rv vention consists inthe construction, arrangement and combination of the various partsof.

Fig. 5 is a vertical sectional view .taken on line 5-5 of Figure 4, and on a scale enlarged from that figure;

Fig. 6 is a plan view of a segment of the conveyor for the machine, showing several indi-y vidual links, or receptacles;

Fig.l 7 is a plan view of the interior of the'dischargingv device with the top plate removed, and a segment of the conveyor shown in dot and dash lines. f

Fig. 8 is a diagrammatic showing of thev relation of successive links or receptacles when pass*- ing through the discharging device;

Fig. 9 is a detail view of a sprocket for driving the conveyor;

Fig. 10 is a cross sectional view of a tooth of the sprocket of Fig. 9; and

Fig. 11 is a side elevational view, similar to Fig. l, of a'modied form of my invention.l

Referring in detail to the drawings, the' machine as a whole includes a base I2 with uprightmembers I4 built thereon for supporting the operatng parts of the machine, which include a hopper or container I6 for thecement and sand material, a discharging device shown generallyy at I8 and a conveyor 20. In the operation of thel in the specication or claims, it'will be under-l stood to include cement, Va mixture of cement and sand, sand alone, or any other dry material.-

Any well-known means Ycan be utilized rfor operating the conveyor. such as an electric motor` substantially uniform,

22 arranged to drive pulley 24 which in turn, through a suitable drive train, operates sprocket 26 mounted on a common shaft with sprocket 2l which engages the conveyor.

In the operation of the device, the conveyor picks up cement from the hopper l5 and carries it to the discharging device I8, where it is discharged through conduit 28 to the point of application.

The hopper I6 utilized in the preferred embodiment is shown clearly in Fig. 3, and consists of a downwardly converging bin having side walls 35 and end walls 3|. The hopper l5 has an upper opening 32 which is disposed at an angle sloping to one side for ease in filling the hopper and is provided with a screen 34. The walls rest on a horizontal plate 36 mounted on the upright members I4 by means of bolts passing through the outturned :Ranges 38 formed in the side walls and bearing plate 36. Openings 45 are formed in the end walls 3i at the lower extremity thereof for the passage of the conveyor 20 therethrough. The openings 40 are formed low and wide to accommodate the shape of the conveyor 25 without unnecessary space surrounding the conveyor. The shape and structure of the conveyor will be described vin detail later. Additional openings 42 are also formed in the end walls 3| at points upwardly from the openings 45 for the passage of the return run of the conveyor 25. A structure 44 forms a channel through the central part of theV hopper I6 and consists of a bottom section 46, rectangular in shape and conforming to the shape of conveyor 20. upon which the upper run of the conveyor bears, and a covering plate 48 of inverted V- shaped formation. The structure 44 is secured to the end walls 3l, surrounding the openings 42, forming an enclosed channel for the passage of the conveyor without the loss of cement material from the hopper i6. The upper surface of the covering plate 48 being inclined enables all the material in the hopper I6 to pass by the channel 44 and not be retarded thereby.

-The conveyor 20 is constructed to form receptacles which will be described in detail later. The lower run of the conveyor 2D passes into the interior of the hopper It, the lower extremity of the hopper being open to the conveyor, whereby the cement in the hopper falls into the receptacles of the conveyor and is carried out thereby.

Referring again to Fig. 1, after the receptacles of the conveyor are lled with cement, they pass in to the discharging device i8.4 Accordingly the lower run of the conveyor 25 passes from right to left as shown in Fig. l, the conveyor sprocket 21 and a similar conveyor sprocket on the opposite end of the machine rotating in a clockwise direction.

The discharging device I8 is supported by two angle irons 55 running longitudinally on opposite sides of the machine and supported by the upright members I4. The discharging device, as shown in Figs. 4 and 5, includes an upper plate 52, a lower plate 54, and two side strips 55, all running longitudinally of the conveyor 25. The upper plate 52 and the lower plate 54 are flat,

horizontally disposed plates, and strips 55 are filler strips to enclose the lateral areas between the plates 52 and 54. The plates 52 and 54, and side strips 56, are of rubber or other resilient material for engaging and sealing the conveyor 2,0 asf it passes through the discharging device i8. The plates 52 and 54 are held as a unit by vertical side retaining plates 58 having inturned 4 ends 55, welded or otherwise secured to the angle strips 56; and a base supporting plate 55 having lateral lugs 62 through which bolts 64 pass and are secured to corresponding lateral lugs S5 formed on the side plates 53. Enclosing the unit is a cover plate 53 which is clamped in place on the unit by yokes 16 which are secured to lugs 'l2 formed on the angle irons 55.

Referring new to the operation of the discharging device !3 and the cooperation between the discharging device and the conveyor, the conveyor as a whole, as well as the individual links forming the conveyor, is of regular outline, that is, in cross section it defines an outer contour having flat surfaces, and in this case being of rectangular formation. The opening formed by the upper plate 52 and the lower plate 54 of the discharging device, and defined laterally by the side strips 55, is also of rectangular formation, since the plates 52 and 54, and side strips 55. have inner flat surfaces. The conveyor 2i) is arranged for passing through this longitudinal opening.

The conveyor is made up of a series of individual links 14, each of which is generally of U-shape in formation. Each link has a cross piece 16 and side pieces i8. rThe cross piece T6 is notched as indicated at at both rear corners for fitting the free ends of the side pieces 18 thereto, the notches 85 being of the same depth inwardly from the sides of the links as the thickness of the side pieces '48, whereby all surfaces of the chainas a whole, when the links are ntted together, present smooth, flat surfaces.

Pins 62 are fitted through openings in the free ends of the side pieces 18 and cross piece 'i6 for pivotally connecting the links together. In Figs. 5 and 6, it will be seen that the various dimensions of the elements forming the links are great, that is, the links are formed heavy and rugged, which must be the case in order to withstand wear. The links 'I4 may be made of metal or any other material which is rigid and will withstand the Wear incident to its operation. De-v fined in each link 14 is an area 84 into which the material falls. Accordingly these areas or pockets 84 form receptacles which convey a considerable amount of material, due to their depth, which, is indicated by the vertical dimension of the receptacle,'as shown in Fig. 5. Each pocket 84 is therefore dened by a continuous perimeter formed by the three sides of one link and one of the sides of the adjacent link, The view of Fig. 6 is in plan of the upper run of the conveyor, and as it is employed in the preferred embodiment,

travels from left to right, since itis the lower run that carries the material from the hopper` i6 to the discharging device I8, the latter, there-` fore, running from right to left. The links 74 dening receptacles 84 are open on 'the top and bottom, and in order to retain the cement material therein, the horizontal plate 3B of the hopper extends up to the entrance of the discharging device I8 (see Fig. 7).

The discharging operation is accomplished by conducting a supply of compressed air through the discharge device I3. "The upper plate 52 and the lower plate 54 are provided with'cavities 85 and 8S, respectively, extendingr entireiy through the plates vertically. These cavities are of a peculiar formation and form an important part of this invention. There is such a relation between the size and shape of the cavities and the-size and shape of the links i4 of the conveyor that an even and uniform ilow of material is insured. The cavities 85 and 88 are symmetrical,

that is, when the plates 52 and 54 are placed in position they register vertically as shown in Figs. 4 and 5. The cavity as shown in Fig. 7 is that of the lower plate 54, and when the plate 52 is placed in position thereover, the outline of the two cavities 86 and 88 form a registering vertically extending conduit or discharging chamber indicated generally at 89. The cavities 88 and 88 are roughly of triangular shape and have one reduced end 90 extending in the direction opposite to the direction of travel of the conveyor and, as shown in plan in Fig. '1, to the right. The lower edge 92 of the cavities 86 and 88 extends longitudinally in the Adirection of the travel of the conveyor 20, and the rear edge 94 extends substantially perpendicular to the line of travel of the conveyor. The edge 96 is diagonally disposed and merges into the edge 94 and the forward end 90 in a curve.

The flrst edge or edges of the cavities 88 and 88. past which the links 14 of the conveyor move as the conveyor passes through the discharge device |8, is called the leading edge and comprises edges 96 and 90. Each end of each Vreceptacle or pocket 84 has a leading edge which first passes the leading edges of the cavities 86 and 88, and a trailing edge which thereafter passes the leading edges of the cavities 86 and 88. Q

4In Figure 7, where the conveyor is shown passing through the discharge device from right to left, the left hand edge of each passage or receptacle 84 is the leading edge and the right hand edge of each passage 84 is the trailing'edge.

It will be seen in Figures '7 and 8 that portions of the leading edges of the cavities 86 and 88 are transverse to the leading and trailing edges of the ends of the passages or receptacles 84 which carry the material. The leading edges of the cavities 86 and 88 are so positioned with respect to the leading and trailing edges of the ends of the material carrying passages 84 that portions of the discharge device adjacent and forward of the leading edges of the cavities cover a portion of the ends of one passage 84 when a portion of the ends of the following passage 84 has just passed the leading edges of the cavities and is beginning to register therewith. In this way a continuous flow of material is maintained at all times.

The conveyor 20 is superimposed on Fig. 7, in dot and dash lines, to show the relation between the receptacles 84 and the cavities 86 and 88. The greatest transverse dimension or width of the discharging chamber 89 is greater than the transverse dimension between the inner edges of the links 14, or the transverse dimension or width of the receptacles 84. The greatest transverse width of the discharge chamber 89 and of the receptacles 84 is measured perpendicular to the direction of the movement of the conveyor through the discharge device I8. Further, the linear dimension of the discharging chamber 89, that is, the dimension running lin the direction of travel of the conveyor, is greater than the linear dimension of each receptacle 84.

The cover plate 68 is provided with a central opening 98 for a conduit |00. The conduit |00 is adapted to conduct a supply of the compressed air from any conventional source and is provided with a pressure gauge |02 and a suitable valve (not shown). The supply of air pressure may be directed into the upper cavity 86, where it forces the material from the receptacles 84 down through the lower cavity 88 and into a spout |04. The conduit 28 is ilexible and leads from the opening of the spout |04' to a conventional nozzle for applying the cement at its point of use. The nozzle itself does not form a part of this invention, and there are a number of types in use. They are constructed for pickingup water by the flow of air and cement therethroughv and mixing it in the nozzle, whereby the cement is applied to a wall yor other surface, as in a.

plastering operation. When the device is used for sand blasting, a nozzle adaptable for that use is employed. ,Y

The upper plate 52, lower plate 54, and side strips 56. may be adjusted toward and away from the conveyor 20 for sealing the links 14 within` the opening through the discharging device I8. by bringing them' into tight engagement therewith. The cover plate 88 is provided withadjusting screws |06 threaded through yoke 10, and bears on the cover plate 68, forcing the latter downwardly into tight engagement with the `top plate 52, and pressing the links of the conveyor 20 downwardly. The side plates 58 have a.l lesser vertical extent than the top plate 52, lower plate 54 and side strips 56 together, leaving a gap |08 to allow for the adjustment just referred to. Similarly the side strips 56 can be broughtinwardly toward the conveyor 20 by means of screws ||0 threaded through the side plates 58 and engaging metal strips ||2 which cover the outer surface of the side strips 56. The side strips 56 seal the links of the conveyor 20 against possible leakage through the points of connection between the individual links.

The effective operation of the discharging device is obtained by the manner inA which the, re-v ceptacles 84 are exposed in the discharging chamber 89 and by the compressed air conducted therethrough. By reference to comparison between Figs. 7 and 8, it will be seen how receptacles 84 enter into the discharging chamber 88 in overlapping relation to each other. Several individual receptacles of the chain 20 are given separate reference numerals to better illustrate this relationship. As receptaclel ||4 approaches the narrow end 90 of the discharging chamber 89, the preceding receptacle ||6 hasentered the discharging chamber to a considerable extent. and the receptacle ||8 preceding the receptacle ||6 has been completely emptied of its material. In the position shown in Fig. 8, the receptacle ||6 has discharged most of its material, and the rate of discharging the remainder is reduced considerably, there being only the concealed area |20 extending outside of edge 96 that is yet to be discharged. After the receptacle ||8 has passed to the-left of the point shown, thereceptacle ||4 enters the discharging chamber 89 .and the initial rate of discharge of the material from that receptacle is slow, and the farther into the discharging chamber it goes, the greater will be` its'rate of discharge of material. At the'samev time the discharge of material from thereceptacle ||6 will be decreased, resulting in substan-J tially uniform discharge of material from the conveyor into the lowercavity 88. In the positions of the various receptacles as shown in Fig. '7, receptacle ||6 has almost completely dis-- charged its material, and the receptacle ||4 has entered into the cavity to quite an extent, such that the rate of discharge of the material from the latter receptacle has reached a considerable proportion and increases and con-v tinues to increase up to a point in the region of the position of the receptacle ||6 as shown in Fig. 8. This procedure continues from' one receptacle to the next, each in overlappingA rela-'- tion with the preceding one, resulting in a substantially even and uniform discharge of material in the aggregate. It will be understood that the position of the receptacle IIB as shown in Fig. 8 may not be the exact point where the rate of ilow of material therefrom begins to decrease, and -I do not wish to be committed to such precision. Nevertheless, it is in that region that the rate of discharge begin to decrease, and about the same time the receptacle H4 begins to enter the discharging chamber. While therate of discharge may not he 10.0 per cent uniform, still it is approximately uniform,

and there is no complete starting and stoppingV such as would produce pulsating dow.

It will -be noted vthat the distance between the edge 90 of the discharging chamber B9, and the right-hand end of the discharging device I8 as shown in Fig. 7, is greater than the linear dimension of a single receptacle 84, or the interior linear dimension of each link. A similar situation is also true with respect to the opposite end of the discharging device i8, that is, the distance between the edge Sli oi the discharging chamber B9 and the left-hand end of the discharging device is greater than the linear dimension of each receptacle 8d. Therefore, it will be seen that the cavities 85 and 88 are aiways sealed against the atmosphere, andiuli force of the compressed air passing there through is exerted on the cement.

Figs. 9 and 10 are views of' the sprocket which is specially designed for the conveyor 2t of the machine. The body of the sprocket is con# ventional in design having usual means for securing it to a shaft, and the teeth |22 are of great thickness and have curved surfaces 2li for engaging the links or" the conveyor 2d. Also they are curved transversely as shown at Sie, for facilitating in engaging the links.

The modied form of apparatus shown in Fig. 11 embodies the same essential parts, but diiers from the previous modication in that the upper run of the conveyor 20 of the present form is utilized for carrying the cement. Accordingly with the hopper l and the discharging device I8 in the same relative positions, the upper run of the conveyor must move from right to left, the conveyor sprockets 21 rotating counter clockwise. In this latter modification, it is .un-4

necessary to have a channel similar to channel1 44 through. the interior of the hopper lli, since,

the return run of the conveyor is beneath the hopper, which simplifies the constructionor` the In other respects the device is theA hopper. same or similar to the device shownin the nrst modification.

Although I have herein shown and describeda. preferred embodiment of my invention, man-` ifestly it is capable of modification and rearrangement o parts without departing from the spirit and scope thereof. I do not, therefore, wish to be understood as limiting this in-v a` single passage therethrough adapted to hold therein the material to be discharged, said discharge block having a conveyor passagewa'yv therein through which said conveyor passes, l af pressurized fluid passageway through said dis intersecting each other, one branch of the intersected fluid passageway being an inlet, the other branch being an outlet, one end of each passage adapted to register with said inlet and the other end of said passage simultaneously registering with the outletas the conveyor passes through said block, whereby pressurized fluid, when applied to said inlet, passes through the registering passages in said material holding members, entrains the material therein, and passes through said outlet; the improvement in said discharge block wherein the leading edges of said inlet and outlet lie transverseto 'the leading and trailing edges of the ends of the passages so that the portions of Athe block 'ad'- ja'cent andforward said leading edges oi' the inlet and outlet cover a Yportion of the ends oi one passage which is partially registering with the inlet and outlet when a portion of the ends of the following passage has passed said leading edges of the inlet and outlet into partial register' therewith, said covered portions of said one passage thereafter passing intoV register with said inlet and outlet,` whereby a continuous flow of material is maintained at all times.

2. A discharge block for use with a continuous conveyor, which conveyor comprises a plurality of similar material holding members, said inem-l bers each having a single passage therethrough adapted to hold therein the material to be discharged; said discharge block having 'a 'coniveyor passageway therein through which said conveyor passes, a pressurized iiuid vpassagewavy through said discharge block,v said passageways in said block intersectingveach other, one branch on the intersected uid passagewaybeing an ina let, the other branch being an outlet, one end of each of said material holding passages adapted to register with said inlet and the other end of each of said passages simultaneously registering with the outlet as the conveyor passes through said block, whereby pressurized iiuid, when applied to said inlet, passes through the registering passages in said material holding members, entraine the material therein, and passes through said outlet; the greatest projected width of said inlet and outlet being greater thanlthe projected width of the ends of said passages and the leading edges of said'inlet and outlet lying transverse to the leading and trailing edges of the ends of the passages so that the portions of the block adjacent and forward of the leading edges of said inlet and outlet cover a portion of: i the ends of one passage which is partially 'registering with the inlet and outlet when a portion of the ends of the following passage has passed said leading edges of the inlet and outlet'and said? moved into partial register therewith, covered portions of said one passage thereafter passing into register with said inlet and outietl whereby a continuous flow of material is 'main-- charged; said discharge block having a con-4 veyor passageway therein through which said conveyor passes, a pressurized fluid passageway through said discharge block, said passageways in said block intersecting each other, one branch' of the intersected fluid passageway being an inlet, the other branch being an outlet, the top end of each said passage adapted to register with said inlet and the lower end of each said passage simultaneously registering with the outlet as the conveyor passes through said block, the leading edges of the inlet and outlet lying transverse to the leading and trailing edges of said passage ends so that portions of the discharge block cover portions of the ends of one registering passage when a portion of the ends of the next passage first begin registering, said covered portions of said one passage thereafter passing into register with said inlet and outlet whereby a continuous flow of material is maintained at all times, said covered end portions of a registering passage, when the following passage rst begins to register with said inlet and outlet, having a length measured from the leading edge of the outlet to that portion of the trailing edge of the passage end which is last to pass said leading edge of the outlet, and the ratio of .i

the height of a vertical passage to said length of the covered portion of the passage end being no greater than the tangent of the angle of repose of the material within the passage, whereby a portion of the material isy retained in the registering passage, until the ends of the next 10 chamber first begin to register with said fluid passageway.

4. A discharge block as set forth in claim 2 wherein portions of said discharge block which bound said conveyor passageway are resilient, and means for compressing adjacent resilient portions against eachother whereby sealing is effected. i

ADOLPH F. LUKES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 674,641 Whittemore May 2l, 1901 743,957 Tompkins et al. Nov. 10, 1903 1,048,019 Wilson 'Dec. 24, 1912 1,712,248 Brayton May 7, 1929 2,156,878 Sinden May 2, 1939 2,262,094 Burt Nov. 1l, 1941 2,299,565 Colburn Oct. 20, 1942 2,314,031 Colburn Mar. 16, 1943 

